A variety of mobile devices now exist which have the capability of determining their own location. Portable navigation devices (PNDs) that include GNSS (Global Navigation Satellite Systems) signal reception and processing functionality are well known and are widely employed as in-car or other vehicle navigation systems. Such devices include a GNSS antenna, such as a GPS antenna, by means of which satellite-broadcast signals, including location data, can be received and subsequently processed to determine a current location of the device. The device may also include electronic gyroscopes and accelerometers which produce signals that can be processed to determine the current angular and linear acceleration. The determined acceleration may then be used in conjunction with location information derived from the GPS signal to determine the velocity and relative displacement of the device and thus vehicle in which it is typically mounted. Such sensors are most commonly provided in in-vehicle navigation systems, but may also be provided in the PND itself.
In recent years, GPS has also been used in systems to warn drivers of speed traps, enforcement cameras and road hazards, such as school zones and accident black spots. In such systems, a device having a GPS antenna and access to a database containing the location of speed traps, accident black spots and other relevant items is typically provided in a vehicle. The device is configured to provide warnings to a driver when the vehicle, using the location information derived from the GPS signal, is in the vicinity of one of the locations stored in the database. One such system is described, for example, in WO 01/55744 A2.
The ubiquity of devices utilising global navigation satellite systems enables a new kind of user-provided input, namely the reporting of the presence or absence of objects at a certain location. Of particular interest are objects relevant to drivers, such as speed limit enforcement devices, traffic congestion, road closures/works, parking locations, etc.
Devices that are capable of sending and receiving location information to/from a database are referred to as “connected devices”. Users of such devices can provide an input, such as pressing a physical or virtual button, to report the location of an object. The current location, typically as provided by the GPS, or potentially by the user, is used to indicate the location of an object. The user can select the type of object (e.g. parking location, speed cam or other) for general purpose devices or may report locations for special purpose devices (e.g. radar trap detectors).                Based upon such user inputs the exact localisation of the object is hindered by:        a) low resolution of the geographical coordinates provided by the device/user;        b) inaccurate reports (i.e. the user selecting the wrong location or reporting when no longer in the vicinity);        c) adversely reported false locations.        
Accordingly, embodiments of the present invention aim to provide a method and system for estimating accurately an object's location, based on statistics of reports from users in the vicinity of the object. In particular, in accordance with embodiments of the present invention the user reports, i.e. geographical coordinates (or “geo-coordinates”) and object type, are collected at a remote server, e.g. in a database, and form the input to the system proposed herein for accurate and robust detection of the object location.